ERBB2 and gastric cancer: This trial found that pembrolizumab was not inferior to chemotherapy, and fewer adverse events were observed.610 Similarly, nivolumab was also tested as a first-line treatment of advanced gastric, gastro-esophageal junction, and esophageal adenocarcinoma in the phase III CheckMate 649 trial.611 Nivolumab with chemotherapy, compared to chemotherapy alone, resulted in significant improvements in OS in patients with a PD-L1 CPS of five or more.611 The PD-1 inhibitor might also benefit HER2-positive GC.